mjhjmtu

nvidia-settings -a [gpu:0]/GPUPowerMizerMode=1

now what is the easiest way to run this one bash line of code at startup???

I am running Gnome 3.14.

You can use gnome-session-properties in terminal or using Alt+F2.

That opens up Startup Applications Preferences in my Linux Mint (could be different for your distro).

Give a name for your command (optional)

Write the bash code in Command option

Add any comment (optional)

Alternatively, you could give a command to execute a bash file (which contains your code) in the commands option.

UPDATE: As notified by don_crissti you have to use gnome-tweak-tool instead. I'm guessing it still has similar options.

If you want to do it with systemd you create a service file as follows:

[Unit]
Description=Execute some nvidia command

[Service]
Type=oneshot
ExecStart=nvidia-settings -a [gpu:0]/GPUPowerMizerMode=1

[Install]
WantedBy=graphical.target

You should save this file with a .service suffix ~/.config/systemd/user/ and enable it with systemctl --user enable filename.service. This way every time you start your session the command will be run. You may add some options to avoid it being run more than once per boot or adjust dependencies so it's executed earlier in the boot process.

Check for problems and status with systemctl status filename.service.

Add this line to /etc/rc.local before exit 0 this will the same when system starts.